Bicyclic molecules with the I ,7 -dia2a-6 ,6-dimethylbicyclo[2 .2 .llheptane and l,8-diaza-7,7-dimethylbicyclo[3.11Joctane (l-aza-7/Mimethyltropane) skeleton are shown to be efficiently synthesized via cyclization reactions of endocyclic tf-acylhydrazonium intermediates. By using a protected p-ketoester as the internal nucleophile, azacocaine analogues are also accessible via this methodology.